High tension cut-out and the like



Nov. 29, 1932. E. N. NORDHEM HIGH TENSION CUT OUT AND THE LIKE Filed June 3, 1929 2 Sheets-Sheet ZLTLTTII ail/177% Nov. 29, 1932. E. N. NORDHEM HIGH TENSION CUT-OUT AND THE LIKE 2 Sheets-Sheet 2 Filed June 3. 1929 PM /A A to the over load condi Patented Nov. 29, 1932 UNETED STATES PATENT OFFICE ERIC N. NORDHEM, OF CHICAGO, ILLINOIS HIGH TENSION OUT-OUT AND THE LIKE Application filed June 3, 1929.

This invention has to do with improvements in high tens i cut outs and the like. The device herein disclosed is particularly in- I to ded for the opening of high tension cir- 'cuits by an arrangement such that the arc is finally extinguished by submersion a movable terminal within a bath of quenchingliquid.

One object of the invention s provide an improved structure wherein the movable terminal is normally maintained under the tension of a spring, tli arrai that the movable terminal is norms strained from movement under the force of such spri by means of fixed abutment on which said movable terminal is ei'igaged, the engagement thereof being normally retained and assured by means of a fusible member. \Vl1en said fusible in? "iber is destroyed due tion the engagement is permitted to be broken that the spring is able to move the movable terminal.

By reason of the above feature the amoun of the force which must be restrained by th fusible member is relatively small and hence a very accurate and d itely controllable operation is assured.

feature of the invention relates to o the provision of construction such that when the movable terminal released by such ful move into contact or close en- 1 a readily removable stationary terminal so that the arc will be drawn from said removable stationary terminal.

runs will avoid unnecessary damage to other parts which can not so readily or economically removed.

Still another feature of n the moveme a of the spring and removable terminal will be readily absorbed by a suitable spring cushion. This will avoid unnecessary shock and consequent damage to the parts.

This feature is especially desirable in this type of device wher sulating or dielectric material. such as glass and the like.

Another feature of the invention relates to Serial No. 367,926.

the provision of a greatly improved and simplified arrangement for securing the fusible element in place. The arrangement is such that this operation can be easily performed without the use of special tools or comp1i cated operations.

A further feature of the invention relates to the provision of a rotary abutment for the movable terminal so that when the fuse element lets go the movable terminal will ride over such rotary abutment with great ease and practically without friction. Consequcntly the frictional. resistance will be practically uniform so that there will be definite assurance that the device will always operate under uniform conditions.

Other objects are to simplify the construction of such devices and reduce the cost of manufacture as well as giving assurance of uniform and consistent operation over long intervals of time.

Other objects and uses of the invention will appear from a detailed description of the same which consists in the features of construction and combinations of parts hereinafter described and claimed.

[a the drawings Figure 1 shows a longitudinal section through a device embodying the features of the present invention, the spring being stretched out in the working position and the movable terminal being set with a fuse in position. In F igure 1 a portion of the device has been broken away so as to shorten up the figure;

Figure 2 shows a view similar to that of Figure 1 with the exception that the fuse has let go and the movable terminal has been drawn down into the quenching bath, and a resetting tool has been extended down and threaded into the upper end of the movable element;

Figure shows a side view of a resetting tool of convenient form, the central portion thereof being broken away so as to shorten the figure;

Figure 4 shows a top plan view of the device of Figure 1;

Figure 5 shows a cross section on the line 55 of Figure 1, looking in the direction of the arrows;

Figure 6 shows a plan detail view of the fuse locking block removed from th rest of the device;

Figure 7 shows an end view of the device of Figure 6;

Figure 8 shows a cross section on the line 88 of Figure 6, looking in the direction of the arrows;

Figure 9 shows a side view of the fuse element removed from the rest of the structure. In this figure the fuse element is shown in its working shape by means of full lines, and by dotted lines tl'iere is indicated its original form;

Figure 10 shows a plan view corresponding to Figure 9;

Figure 11 shows a detail view of the roller abutment, the same being partly in section;

Figure 12 shows a detail side view of the screw plug which goes into the top end of the movable terminal;

Figure 13 shows a perspective view of the renewable burn off terminal;

Figure 14 shows a longitudinal section through the movable terminal with the pigtail inserted into its lower end, but before the same has been clamped.

Figure 15 shows a view similar to that of Figure 14, but with the lower end of ti e terminals clamped together and riveted to the spring connectors; and

Figure 16 shows a perspective view of the spring connector.

Figures 6 to 16 inclusive are on an enlarged scale as compared to Figures 1, 2, s2 and 5.

The device illustrated includes a tubular chamber or casing 17 made of strong glass, fibre, or other suitable insulating material, a cap 18 is placed on its lower end which is thereby closed by said cap, and a ferrule 19 is placed on the upper end of the tube. This cap and ferrule are sealed in place in any convenient manner as by means of solder 20. The ferrule 19 is preferably provided with inwardly reaching ring or shelf portion 21, which partly overlies the upper end of the shell 17 and establishes a seat for the fuse locking device and for the abutment of the movable terminal presently to be described.

\Vithin the chamber 17 is located the spiral spring 22. This spring is a tension spring; and its lower end is connected to a block 23 which is for this purpose provided with a spiral into which two or three turns of the lower end of the spring may be threaded. There is a block 24 preferably of rectangular form, the lower end 25 of which is threaded and may be screwed into a boss 26 reaching up from the cap 18. This member 241 carries a cross pin 27 which seats against the top face of the block 28 so as to retain i through the device. This connection 11 ay be established in any convenient manner.

For example the upper portion of the block 24: may be drilled to receive the lower end of the pig-tail, and then said upper portion may be pinched or squeezed to flatten it out and therebyclamp the pig-tail as shown at 29 in Figure 1.

There is'a movable terminal 30 which is connected to the upper end of this pig-tail 28. Said terminal 30 preferably comprises a block of copper or brass, the lower end of which drilled as shown at 31 to receive the upper end of the pig-tail.

This portion may then be squeezed and flattened out as shown in Figure 15 in particular.

The movable terminal 30 has at one side a recess or notcri 32 the to surface 33 of which is formed on an angle or slant which may be found appropriate for the best operation of the device as will be presently explained.

The upper end of the spring 22 is connected to the movable terminal 30 in any convenient manner. For this purpose I have illustrated a pair of plates 3% and 35 which have the radially extending wings 86, said wings being provided with p rforations 37 through which may be threaded. e convolutions of the upper end of the spr The central portions of t iese plates S-Il and 35 rest against the flattened side faces of the lower portion of the movable t rininal 30, and may be secured in place by a rivet 38 extended through all of the pi. rts as clearly evident from Figure 15.

By meats of the above arrangement the movable i '.a. 30 is very securely connected to the pi -sail and at the same time a very convenient connection for the upper end of the spring is established.

Normally casing 17 is filled. with quenching liquid up to about the level indicated at 39 in Figures 1 and 2. Normally also the movable rininal is retained at a position above said level. When the fuse lets go the movable terminal is drawn violently down by the spring below the surface of the liquid until finally the spring closes up as shown in Figure 2. This sudden closing of the spring will naturally cause a severe shock to the parts. In order to prevent damage, es pecially to the more or less fragile shell 17, l have provided a cushion to talre up this shock. The same is illustrated as a spring l0 located between the block 23 and the cap 18. Said spring is preferably composed of two or three turns of spiral and is preferably installed un a certain amount of compres sion. This compression is produced by the threading of the lower end of the block 24 into the boss 26 as already explained.

In order to give additional mass to the block 42 so as to more completely absorb the shock of the arresting of movement of the spring 28 and terminal 30,1 prefer to establish the sleeve or tubular portion 41 as a continuation of the block 42 which lies between the block 23 and the spring 40. By making the sleeve 41 and block 42 of metal they will have a considerable mass or weight and corresponding inertia.

There is an abutment member 43 located in the upper end of the device and above the position of the flange 21. The same is preferably of more or less rectangular form as shown in Figure 6. It is split or divided on one side as shown at 44 so as to establish an inverted V-shaped opening. WVithin this opening there is located a spreading block 45 which when drawn upwards will spread the member 43 so that its arms 46 and 47 are forced apart. The corners 48 and 49 of said arms will thereupon be compelled to ride against the interior surface of the upwardly extending flange 50 of the ferrule with the result that the member 43 will be forced in the direction of the arrow in Figure 6. The wedge block is provided with grooves 43a in its side portions which receive the edges of the slotted opening 44. Consequently the wedge block is prevented from turning while its vertical sliding movement is not interfered with.

The opposite or connecting side 51 of this member 43 is preferably curved to conform to the inner surface of the flange 50 of the ferrule so that the clamping action just referred to will tend to clamp the portion 51 firmly against said flange.

The block 45 may be drawn up for this clamping action in any convenient manner, as by means of a screw 52 the upper end of which can be conveniently reached from the upper end of the device when uncovered.

The head of the screw 52 seats against a plate 53 which overlies the upper end of the slotted opening 44 and rests upon the top surface of the member 43. This plate 53 has a downwardly depending arm 54 which reaches down through the member 43 and occupies a position relatively close to the movable terminal 39 when said terminal stands in the raised or set position as shown in Figure 1. The parts do not, however, actually connect with each other at this time.

There is an abutment which extends across the member 43 and receives the notch 32 of the movable terminal so that as long as the movable terminal is held sidewise with its notch in engagement with such abutment, the terminal is restrained from moving downwards. Upon relieving said sidewise restraint however, the movable terminal may 1 slip over the abutment and be drawn down by the spring 22. In the particular construction illustrated, this abutment comprises a small roller 55 illustrated in detail in Figure 11. It has a central shank portion 56 which receives the notch 32 of the movable terminal; and said roller has the enlarged end portions 57 and 58. These provide sockets, the inner surfaces of which are lined with insulating material 59, such as bakelite or hard rubber as shown in Figure 11. Bearing studs may then be set through the openings 60 and 61. of the member 43 and into the sockets 62 at the ends of the roller so as to establish journals upon which the roller can rotate. The roller is also thereby insulated from the member 43.

A fuse device is provided, such as shown in F igures 9 and 10. It includes a strip of fusible conducting material 63 which has one end connected to the movable terminal 30 and the other end in connection with the flange 59 of the ferrule 19. This fusible link possesses a certain amount of tensile strength which may be availed of in order to hold the movable terminal 30 againstshifting sidewise on the roller 55 until the fr e blows. Ordinarily, however. it will be desirable to supplement the tensile strength of the fuse itself by means of another strip 64 of some other material such as steel or brass which has a much greater tensile strength but is not suitable for as a fuse element. The strips 63 and 64 are separated by a strip of insulating material 65 laid bet een them as best shown in Figure 9. The left hand ends of these strips are preferably somewhat enlarged shown in Figure 19 and provided with the perforation '6 to receive the threaded shank 67 of a clamping stud 68 Such shank 67 may be threaded through into the socket 69 on the upper end of the movable terminal 36 so as to clamp the end of the fuse device between the parts. The block 68 is preferably provided with a through opening 70 to receive a pin by means of which said block may be conveniently turned during the clamping operation.

The other end of the fuse device is preferably folded. at right angles as shown in Figure 9 so that the end portions of the strips 63, 64, and 65 are first folded down and then the ones of the strips 63 and 65 are folded back up at the outside of the device so as to clamp the strip 64 between ther It will be understood that the illustrations of F igures 9 and 16 are on exaggerated seal The vertical portion 71 of the fuse device seated between the surface 51 of the member and the inner surface of the flange 50 of the ferrule 19. Consequently, when themember clamped, the surfaces of the fuse strip 63 are firmly engaged by the member 43 and the ferrule 19, but the strip 64 remains insulated from these parts.

As a result of the above arrangement the strip 64 supplies the full benefit of its tensile strength to hold the movable terminal 30 normally hooked on to the abutment member, but the entire body of the electric current is compelled to flow through the link 63. When said link burns 05, due to overload, the arc will immediately burn the insulation strip 65 and will then burn away the strip 64 so as to finally release the movable terminal 30 from any further retention. The top surface 33 of the notch 32 is formed on such an angle that the spring 22 will immediately be able to pull the movable terminal downwards accompanied by a sidewise movement thereof as it rides over the abutment. Said movable terminal will then be slid past the fixed terminal 54. Since said fixed terminal is in electrical contact with the member 48 and with the ferrule 19 the arc will be drawn between the terminals 30 and 54. These terminals can be readily replaced when damaged to such an extent that they are no longer usefill.

The upper end of the device is preferably normally protected by a cap which can be readily removed. This cap takes the form of a ring 7 2 which can be secured to the ferrule 19 by the screws 73. Said ring 72 is shouldered as shown at 74 and a clamping ring 75 may be set in place from below when the ring 72 has been removed from the ferrule. A disc of material 76 such as tinfoil or oil-paper is set into place and is then clamped in place by forcing the ring 75 home. This will insure a gas-tight seal which will prevent loss of liquid by evaporation; but said seal will give way under a relatively small pressure so as to break before any explosive damage might be done to the shell 17 or other parts.

When the device has operated it may be readily reset by the use of a simple tool such as the rod 77 having its lower end threaded as shown at 78 to enter the block 68 as shown in Figures 2 and 12. The upper end 79 of this rod is preferably looped so that it can be conveniently grasped.

Upon removing the cap 72 as shown in Figure 2, the screw 52 may be loosened-up so that the device 43 can be removed, together with the burned-off portion of fuse. The folded portion 71 of a new fuse may then be set into place and the member 43 may be set back into place and the screw 52 again tightened up. During this operation it is convenient to have the fuse device turned into the straight form shown by the dotted lines of Figure 9.

The tool 77 may be then set down through the shell 17 and have its lower end 78 threaded into the block 68. The movable terminal may then be pulled back up into the working position, thus again stretching the spring, and upon hooking the notch 32 over the abut ment 56 a small wedge may be temporarily set between the movable terminal 30 and the burn-ofl terminal 54 so that it will hold the movable terminal temporarily in place. Thereupon the block 68 may be unscrewed from the movable terminal 30 so as to release the end portion of the burned-elf fuse. The end of the new fuse may then be turned down into the horizontal position such as the full lines of Figures 1 and 9. Thereupon the block 68 may be again screwed into place and tightened up so as to clamp this end of the fuse. Upon completion of this operation the temporary wedge may then be removed and the fuse will then serve its function of holding the movable terminal in the reset or normal position.

A new diaphragm 76 may then be set into the cap and thereupon the cap may be screwed into place on the ferrule 1 liquid destroyed or wasted during the previous operation should be replaced before the cap set into place.

The clips 34 and be permanently at-' tached to the convolutions of spring which are threads through them, by soldering or otherwis if desired.

A cap '59 having the downwardly extend- 80 and inturned lingers 81 may be "op of the device to protect the and other parts. The fingers are separated from each other and there are relat vely large vent openings between that at the instant of rupture of the n the gases may freely escape and .-.l. rain on the shell'lZ. Also the cap '79 will prevent entranc of rain or snow or elements into the shell after the diaphragm 78 has been ruptured and prior to refilling and insertion of a new diaphragm.

ll hile T have herein shown and described only single embodiment of the features of my present invention, still I do not intend to limit myself thereto except as I may do so in the claims. 1

I claim: 1. i cut out device comprising in coma tubular casing of insulating ma- .tain en a ement of the movable terminal with the abutment, and serving to release the movable terminal to permit lateral movement thereof for disengagement from said abutment when the fusible device is destroyed,

aid casing having lower end ansaid closed end and its upper end notch, a fusible Naturally any and a replaceable burn-oft terminal located in proximity to the path of travel of the movable terminal when released from said abutment, substantially as described.

2. A cut out device comprising in combination a spiral tension spring, means for anchoring its lower end, a movable terminal connected to the upper end of said spring and provided with a transverse inwardly reaching notch in one side, a horizontally extending roller abutment engaging said notch, the top surface of the notch extending inwardly and downwardly at a suflicient angle to permit the movable terminal to move sidewise for disengagement from the roller abutment under the downward force of said spring, means for normally retaining the movable abutment against sidewise movement under the force of the spring, said retaining means comprising a fusible device having one end connected to the movable terminal and. the other end anchored to a sta tionary part in a position to restrain lateral shifting of the movable terminal for disengagement from the abutment, together with a renewable burn-off terminal located adjacent to the path of travel of the movable terminal when released by said fusible device, said burn-off terminal being sufficiently removed from the normal position of the movable terminal to permit free lateral and downward movement of the latter when released by destruction of the fusible device, substantially as described.

3 A cut out device comprising in combination a movable terminal, spring means normally tending to move the same longitudinally to a circuit opening position, there being an inwardly reaching transverse notch in said movable terminal, a transverse abutment ,in position to be engaged by said notch to thereby restrain the movable terminal against longitudinal movement of the force of said spring, the engaging surface of the notch being formed on an angle to insure disengaging movement of the terminal from the abutment accompanied by lateral movement of the terminal under the force of said spring, and means for restraining the movable terminal comprising a fusible device having one end connected to the movable terminal and the other end connected to a stationary part whereby said fusible device is subject to tension due to the tendency for'lateral movement of the terminal under the tension force of the spring, together with a burn-off terminal located adjacent to the path of travel of the movable terminal but sufficiently removed from the normal position of the terminal to prevent interference with the lateral movement of the terminal during disengagement from the abutment, substantially as described.

4. A cut out device comprising in combination a movable terminal, spring means normally tending to move the same longitudinally to a circuit opening position, there being an inwardly reaching transverse notch in said movable terminal, a transverse abutment in position to be engaged by said notch to thereby restrain the movable terminal against longitudinal movement under the force of said pring, the engaging surface of the notch being formed on an angle to insure disengaging movement of the terminal from the abutment accompanied by lateral movement of the terminai unoer the force of said spring, and means for restraining the movable terminal comprising a fusi le device having one end connected to the movable terminal and the other end connected to a stationary part whereby said fusible device is subject to ten sion due to the tendency for lateral movement of the terminal under the tension force of the spring, substantially as described.

5. A cut out device comprising in combination a movable terminal, spring means normally tending to move the same longitudinally to a circuit opening position, there being an inwardly reaching transverse notch in said movable terminal, a transverse abutment in position to be engaged by said notch to thereby restrain the movable terminal against longitudinal movement under the force of said spring, and means for restraining the movable terminal comprising a fusible device having one end connected to the movable terminal and the other connected to a stationary part, whereby said fusible device is subject to tension in holding the movable terminal in place with its notch engaging said abutment, substantially as described.

6. In a cut out device comprising in combination a movable terminal, there being an inwardly reaching transverse notch in said movable terminal, a transverse abutment in position to be engaged by said notch to thereby restrain the movable terminal against longitudinal movement under the force of said spring, and means for restraining the movable terminal and for retaining the same with its notch in engagement with the abutment, including a device which is fusible under overload current, substantially as described.

7. A cut out device comprising in combination a movable terminal, means for normally restraining the same against longitudinal movement, said means being so constituted as to require lateral movement of the ter minal coincidentally with longitudinal movement, spring means normally tending to cause such longitudinal movement, and means for normally resisting the lateral movement of the terminal to thereby coincidentally prevent longitudinal movement of the terminal, said means including a part subject to destruction by burn-off with overload of current the center line of said part intersecting the center line of the movable terminal, substantially as described.

8. A cut out device comprising in combination a movable terminal, means for normally restraining the same against longitudi nal movement, said restraining means being so constituted as to coincidentally require lateral movement of the terminal, spring means normally tending to produce said movements, and means normally constituting a portion of the electric circuit for re straining such lateral movement of the terminal, and being subject to destruction by overload of current the center line of said means intersecting the center line of the movable terminal, substantially as described.

9. A cut out device including in combination a shell of frangible material having a fixed abutment at one end, spring tension means within said shell having one end secured to said abutment, a movable terminal connected to the other end of said spring tension means and normally restrained against movement but subject to release from such restraint with over load of current, to thereby permit the spring tension means to function rapidly, and other spring cushioning means intermediate between the end of the frangible container and the movable parts and subject to impact from said movable parts when their movement is arrested, substantially as described.

10. A cut out device including in combination a shell of frangible material, a tension spring therein, a terminal block secured to one end of said tension spring and located adjacent to the end of the frangible container, a movable terminal connected to the other end of the tension spring, means for normally restraining movement of said terminal under the force of the spring, and cushioning means intermediate between the terminal block and the end of the container and subject to impact upon arresting movement of the spring and the movable terminal to thereby relieve the frangible container of shock, substantially as described.

11. A cut out device including in combination a spiral spring, a terminal block secured to one end thereof, a movable terminal secured to the other end of said spring, means normally restraining the movable terminal from movement under the force of the spring, means for restraining the terminal block from movement under the tension of the spring, and cushioning means in engagement with the terminal block to cushion shock of the same when the spring closes up due to arresting movement of the spring and the movable terminal, substantially as described. 12. As a new article of manufacture, a fuse device for the purpose specified, comprising in combination companion links of metal, one of said links being composed of conducting metal having a relatively low fusing point and the other link being composed of metal having a'relatively high tensile strength,

- a strip of insulating material located between the links, the link of. fusible metal and the strip of insulating material being longer than the other link, and projecting beyond one end of said other link, and being folded over said end of said other link, whereby the,

fusible link is presented at both sides of said end of the other link and is efiectively insulated therefrom, substantially described.

13. As a new article of manufacture a fusible device comprising in combination two links of metal, one of said links being composed of conducting metal having a relatively low fusing point and the other link being composed of metal having a high tensile stren th, and a layer of insulating material located between the two links, said layer of insulating material being longer than the second mentioned link and projecting beyond one end thereto and folded over said end so as to insulate and protect both sides thereof, substantially as described. i

14. Asa new article of manufacture, a fusible dev ce comprising in combination a pair of metallic links, at least one of which is composed of conducting material having a relatively low fusing point both of said links being fusible under overload current, together with a layer of insulating material located between said links and extending over and protectin both faces of one end of the other 16. As a new article of manufacture a fusible device comprising a pair of metallic links insulated from each other at at least one end and mechanically connected together at the other end, at least one of said links being composed of conducting material having a v relatively low fusing point and both of said links being fusible under overload current, substantially as described.

17. As a new article of manufacture, a fusible device comprising a pair of metallic'links insulated from each other atat least one end and mechanically connected together at the other end, at least one of said links being composed of conducting material and both of said links being fusible under overload current, substantially as described.

ERIC N. NORDHEM. 

